SCM

Apollo can currently get commit data only from Github, although this should be pretty easily extended.
If you are not setting a Github user and token in the settings, Apollo will use the public API access, meaning it can only view public repositories, and subjected to fairly low rate limit.

If you set the permissions in the configuration than apollo will act as a normal user in Github and will be able to view all private repositories the respected user have access to as well and will be subject to a much higher rate limiting.